Looper-operating mechanism for sewing-machines.



PATENTED DEG. 81, 1907.

L. ONDERDONK.

LOOPER'OPERATING MECHANISM 'FOR SEWING MACHINES.

APPLIOATION FILED NOV. 9. 1901.

2 SHEETSSHEET l.

I q/Vunmsoeo No. 875,671. PATENTED DEC. 31, 1907. L. ONDERDONK.

LOOPER OPERATING MECHANISM FOR SEWING MACHINES. v

APPLICATION FILED NOV. 9. 1901.

2 SHEETS-SHEET 2.

UNI 0 N lg l S 4 QT 9 k 1|! fit 0 l x w a v m d N w 1 MM a UNITED STATES, PATENT omcE.-

LANS NG o DEaDoNK, QFINEW YonkgN. Y., ASSIGNOR ,1 O UNION SPECIAL SEWING MACHINE COMPANY, or CHICAGO, ILLINOIS, -A coaroRArIoN or I-LLINois.

LoorEn-ommmc iron snwme-mncmmas.

I Specification of Lettersratent. 4 Application 51st November? 1901. Serial No. 81.760.

Patented Dec. 31, 1907.

a citizen of the United States, residing at' New York, in the county of New York, State.

of New York, have invented certain new and useful Improvements in Looper-Operating Mechanism for Sewing-Machines, of which the followin is a description, reference bemg had to t e accompanying drawing, and to the letters and figures'of reference marked thereon. p My invention relates to an improvement in sewing machines of the chain stitch type, the object being to provide a stitch which is capable of bein drawn up'closely into the oods, and whic in appearance'on the un er side so closely resembles a lock stitch as to be scarcely distinguishable therefrom, thereby gaining all the advantages attendant upon the useof a chain stitch over a lock stitch,-and at the same time, avoiding the objections existing to the use of a chain stitch upon certainclasses of work, namely that the same could not be properly drawn up into'the goods, so as to avoid a ridge due to the accumulation of threadon the under side; and that the stitch did not .look alike on both sides. These features are particularly desirable in shoe work, or other work Where the material is such that the stitch needs to be practically buried in the goods. In general, to accom lish'this result, I have provided a machine in which the needle and thread-carrying looperare so arranged and the looper mechanism so timed and operated that the looper moves into the loo then there is a cessation of the longitudina movement thereof while the sidewise or'n'eedle avoiding movement is taking place, and then a quick withdrawal of the loo or from the needle loop immediately after t e oint -0f the needle has passed into the looper oop,

. the looper having a variable movement im partedto it'by means of connections operated from the needle lever extension. By this arrangement the looper sheds the needle 100 so the stitch can be drawn up quickly, and firmly, and the use of a take-up for the loo er thread is dispensed with.

he invention therefore, consists in the arts, improvements and arrangements heremafter shown and described and set forth in the claims.

The invention is illustrated in the accom-- panying drawings, in which Figure .1 is a side elevation of a sewing machine, embodying my invention, the

cloth plate and certain parts non-essential to an understanding of theinvention'being re moved; Fig. 2 is a sectional plan view on line 2-2, of Fig. 1; Fig. 3 isa erspective view illustrating the connection etween the needle lever extensionand looper operating pitman; Fig. 4 is a cross section illustrating'the sidewise movements of the looper; and Fig.

5 is a detail perspective of theintermittent mechanism for the up er thread.

I n t eseidrawings, the mac ine is in general of the well known Union Special type, the bed plate A, goose neck B, needle leverC, needle bar D, feeding mechanism, and other usual parts, such as. the looper rocker E, oscillating looper rocker and sup orting yoke, F, the cam G, and fork -H, being of well known construction.

The looper I is a threa'd'carrying looper and is su ported in a socket in the rocker in the usua Way, but the looper itself is shorter than those ordinarily in use, and has a short throw, this featureit being possible to embody by reason of the operating mechanism for the looper hereinafter described. In the Union Special machines,.as ordinarily constructed, the looper had its forward and backward movement in the direction of its length, imparted to it by a' itman connec- .tion between the looper roc er and the extension of theneedle lever. In the resent instance, I retain the pitman rod'K, ut interpose between it and the needle lever exten* sion O a rocking lever and link mechanism for imparting variable speed to the looper, this mechanism including the following mechanism. j

The needle lever extension C is provided at its lower end with a short shaft or stud L, screwed into it, one end of a link M'being ivoted thereto, the other end of said link eing screw-threaded to receive the end of a stud N, which passes through the end of an arm or crank O, on the rocking sleeve P,

j ournaled in a stud or short shaft Q screwed :end of the pitman rod K.

Itwill be seen that this constructionprovides a compound togglelever mechanism for operating the looper, of which the needle leverextension, the link 'M and the rocking crank 0 form one part; and the rockin crank R, the ball ,j oint and the pitman rod 1% form the other. It will be seen also, that the needle lever extension, the link M and the rocking crank 0 form a differential mechanfro rnthat of the crank R. I ave therefore,

provided two differential mechanisms be tween the needle lever extension, and the looper, one of which conveys its movements through the other. By this arrangement of parts, the looper may be givena greatly exat which the cranks O, R, begin to rise. Then tended dwell at the end of its stroke and a very high speed intermediate the ends of its stroke. 1

=As the needle is moving upward and the looper moving forward, the screw or projection S on the needle lever C, rides on the spring nipper plate T and causes the same to grip the needlethread between it and the plate U on the goose neck, and prevents pulling .off of thread during the upward movement of the needle, thus setting the stitch and roperly drawing it up. into the goods. it Wlll be noticed by referring to the drawings, that when the needle begins to move upwardly, the lower end of the needle lever extension 0 moves forward. The link M moves toward the vertical position, swinging forward the cranks O, R, and moving the looper quickly into the needle loop but when the dead center is reached the cranks remain stationary and the further forward movement of the needle lever extension, due to the completion of, the upstroke of the needle, merely serves to swing the" link M. and its pivot N independent of the cranks, and during this period the sidewise movement of the looper takesplace, which sidewise movement ceases when the needle lever extension has reached in its backward movement, the point the looper starts backward slowly, but increases its speed, and movesout of the needle loop'ouickly, allowing the stitch to be drawn up as the needle moves up.

The looper may be very short and has a short throw, the needle taking the looper loop near the point of the looper, and allowin the looper to back immediately out of the cop, and also to enter the needle loop quickly, which is desirable in overcoming the liability to skip stitches and'also obviates the necessity of throwing out as large a loop as is common in chain stitch machines.

I am aware that it is not new broadly to provide variably speeded loop-taking devices, but my invention differs fromidevices heretofore proposed, not only in the details hereinafter claimed and above described, but also in the manner and time in which the variable' movement takes place, and in the results accomplished, the main feature of the present invention being the fact that the forward movement of the looper into the loop 'or toward'the center of its movement, is a quick one, which is of especial advantage in avoids the liability of skipping stitches; then an inactive period while the needle avoiding movement is taking place; then it starts back slowly but has a very quick movement out of the loop when the needle oint' has. )assed into the looper loop to enab e the stitc to be drawn up quickly as the needle moves up; this isperhaps the most important feature of the present invention, and one which clearly distinguishes from the prior art, for by this arrangement, the looper sheds the needle loop quickly, and the use of a take-up for the loo thread is dispensed with.

arious minor modifications and changes may be made, without departing from the spirit of my invention.

Having thus described my invention, what I claim as new and desire to secure by Letters Patent, is

1-. In a chain stitch sewing machine, stitch-forming mechanism including a needle lever having an extension, a needle and a cooperating thread-carrying looper, and

-means for imparting forward and backward movements to said 0 oper, to take and leave the needle loop, said means including devices forimparting to said looper a relatively slow forward movement in the direction of its length until it is about to enter the needle loop, as the needle is ascending, a

relatively quick movement into the needle .a looper having a very short throw, for it loop, a relatively slow further forward movement, and an initial slow backward movement, and a relatively quick backward movement as it is about to leave the needle loop, and the needle in its descent passes into the looper loop, and a relatively slow final backward movement, said looper gperating means including a pitman, and variable speed mechanism inte osed between one end of the pitman and t e needle lever extension; substantially as described.

2. In a chain stitch sewing machine, stitch-forming mechanism including a needle and a cooperating thread-carrying looper,

, and means for imparting forward and backward movements to said looper, to take and leave the needle loop, said means including devices for imparting to said looper a rela' tively slow forward movement in. the direction of its length until it is about to enter the needle loop, as the needle is ascending, a relatively quick movement into the needle loop, a relatively slow further forward move ment, and an initial slow backward movement, and a relatively, quick backward 7 ment, and a relatively quick backward movement as it is about to leave the needle loop, and the needle in its descent passes into the looper loop, and a relatively slow final backward movement, said devices including a pitman and variable speed mechanism interposed between one end of the pitman and the needle lever extension, said variable speed mechanism comprising rocking cranks, one of which has a pivotal link connection with the needle lever extension, and the other of which is movable uniformly'with the first crank and is operatively connected with the pitinan, substantially as 3. In a chain stitchfl sewing machine, stitclnforming meclianislrfincluding a needle and a cooperating thread-carrying looper, and means for imparting forward and backward. movements to said looper, to take and leave the needle loop, said means including devices for imparting to said looper a relatively slow forward movement-in the direction ofits length until it is about to enter the needle loop, as the needle is ascending, a relatively quick movement into the needle loop, a relatively slow further forward move-- ment, and an initial slow backward movemovement as it is about to leave the needle loop, and the needle in its descent passes into the looper loop, and a relatively slow "final backward movement, said devices including a pitman, and variable speed mechanism interposed between one end. of the pitman and the needle lever extension, said variable speed mechanism including a link pivoted to the needle lover extension, a crank arm pivoted to the link at one end, and at its oppositeend to the machine frame, a second crank arm secured to the first crank arm and pivoted at its opposite end to the looper-operating pitman; .substan tially as described.

4. in a chain stitch sewing machine, stitch-forming mechanism including a needle and a coi'iperating thread-carrying looper, and means for imparting forward and backward movements to s 'd looper, to take and leave the needle loop, said means including devices for imparting to said looper a rela- Tively slow forward movement in the direction of.its length until it is about to enter the needle loop, the needle isascending, a relatively quick mo ement into the needle loop, a relatively slow further forward movement, and an initial slow backward movement, and a relatively quick backward movement as it is about to leave the needle described loop, and the needle in its descentvpasses into the looper loop, and a relatively slow final backward movement, said devices including a swinging lover, a 'llIlk plvoted thereto, a crank'arm pivoted to the lirik at one end, and at its opposite end to the'machine frame, a second crank arm secured to the first crank arm, and pivoted at its opposite end to the looperopera ting rod; substantially as described.

5. In a sewing machine, stitch-formin mechanism including a needle,a looper an a loo er support, and means for operating said ooper support includin a com ound toggle lever mechanism; su stantially as, described. j.

6. A sewing machine including in combination stitch forming mechanism, comprising a needle, a looper and a looper support and means for imparting a variable movement to said 100 er support including a plurality of toggle. evers, one of which imparts its motion to the looper through the other; substantially as described.

7. In a sewing machine, stitch-forming mechanism including a needle and a loo er, and means for operating said looper inc uding a compound tog le lever mechanism, said com ound toggle ever mechanism comprising t e needle lever extension, the link pivoted to the lower end thereof, the rocking crank having pivotal connection with the link, the second rockin crank secured to the first rocking crank, an a pitman rod having a ball and stud connection at one end with the rocking crank and at the other end with the looper rocker; substantially as described.

8. A sewing machine including in combination, stitch forming mechanism, compris ing a needle lever having anvextension, a needle, -a thread-carrying looper, a looper support and means for imparting a variable movement to said looper support and looper from the said needle lever extension, including a plurality of differential mechanisms, one of which im arts its motion to the looper through the otier, whereby said looper is moved forward first slowly, then rapidly into the needle loop and then slowly to the end of its stroke.

In testimony whereof I allix my signature, in presence of two witnesses.

LANSING ()NDERDONK.

. Witnesses:

W. H. BoYER, J. H. HOWELL. 

